Cannot find tags with "." in name

[lawremi]

It looks like helm-gtags-dwim and helm-gtags-find-tag-from-here fail to find tags with a period (".") in their name. Perhaps this is due to how thing-at-pt parses symbols. Is there any way to work around this? helm-gtags-find-tag does make the correct auto suggestion.

[syohex]

Could you tell me your use-case in more detail ? I think tag name(function, class/struct field, variable name) does not contain .(dot) in C, C++, Java, PHP.

[lawremi]

Not in those languages, but unusual languages like R do allow . in symbol names and it is actually quite common. It would be great to have a variable that one could set when entering a specific editing mode. It would allow a custom pattern for extracting symbols.

[syohex]

What major-mode do you use in such case ? If it does not treat . as symbol, mode implementation is wrong.

You can fix by adding following configuration in your hook function

;; Please replace `some-mode' with your major-mode
(defun my/some-mode-hook ()
  (modify-syntax-entry ?. "_" some-mode-syntax-table))
(add-hook 'some-mode-hook 'my/some-mode-hook)

[lawremi]

Hmm, well, it looks like the mode (ess) is already allowing .. See here. Perhaps something else is wrong?

[syohex]

Please check . syntax by M-x describe-syntax. Could you show me test code of this issue and ess configuration for reproducing this issue ? (I don't know ess well).

[lawremi]

I think it would be tough to reproduce right now, because it depends on a way to build a gtags index for R code. I've written one, but it's not yet cleared by the lawyers for release ;) The syntax table looks good though, because it contains this line:

.               _   which means: symbol

But when I index an R function like:

foo.bar = function(x) { x }

And then put the point on a call like:

foo.bar(x)

I get the error: "foo.bar: not found" even though I can find it in the index with e.g. helm-gtags-select.

If I change the function name to foobar, everything works.

[rdiaz02]

I have the exact same problem, also with R. I generate the GTAGS file with a call to gtags, for instance. I have configured my ~.globalrc so that the default uses also pygments, and this works just fine with global from the shell.

Minimal example: steps

1. Install ess. The default will do.

2. (This I am not sure how much it matters). My .globalrc file has:

   default:\
      :tc=pygments-parser:tc=gtags:
   native:\
      :tc=gtags:tc=htags:
   pygments:\
     :tc=pygments-parser:tc=htags:

   (so that pygments is always used in addition to gtags in the default). And the pygments-parser part has these lines (though I do not recall modifying anything here).

   :langmap=S\:.S.R:\
   (...)
   :gtags_parser=S\:/usr/local/lib/gtags/pygments-parser.la:\

   (Of course, I can share my complete .globalrc if needed).

3. Open a buffer and call it, say, f1.R and copy the following code (you should see the modeline display ESS[S]):

   foo.bar <- function(x) return(x)
   foobar <- function(x) return(x)
   3 + foo.bar(4)
   5 + foobar(4)

4. Do helm-gtags-create-tags
5. Place cursor on the last line, on foobar: with helm-gtags-dwim one jumps to the definition. Not so if you are on the one before last line (3 + foo.bar(4)): here I get foo.bar: not found.
6. In the shell do global -x foo.bar and check that global can indeed find the definition. In my case I get foo.bar 1 f1.R foo.bar <- function(x) return(x).

Syntax table

I just did the M-x describe-syntax and this is what I get (only showing what I understand to be the relevant entries; let me know if you need anything else)

C-j     >   which means: endcomment
"       "   which means: string
#       <   which means: comment
$       _   which means: symbol
% .. &      .   which means: punctuation
'       "   which means: string
* .. +      .   which means: punctuation
-       .   which means: punctuation
.       _   which means: symbol
/       .   which means: punctuation
:       _   which means: symbol
< .. >      .   which means: punctuation
@       _   which means: symbol
\       \   which means: escape
_       _   which means: symbol
`       "   which means: string
|       .   which means: punctuation

The parent syntax table is:
C-@ .. C-h  .   which means: punctuation
TAB .. C-j      which means: whitespace
C-k     .   which means: punctuation
C-l .. RET      which means: whitespace
C-n .. C-_  .   which means: punctuation
SPC         which means: whitespace
!       .   which means: punctuation
"       "   which means: string
#       .   which means: punctuation
$ .. %      w   which means: word
&       _   which means: symbol
'       .   which means: punctuation
(       ()  which means: open, matches )
)       )(  which means: close, matches (
* .. +      _   which means: symbol
,       .   which means: punctuation
-       _   which means: symbol
.       .   which means: punctuation

[Pierre-Andre]

I have the exact same problem, also with R. 1) I generate the GTAGS file with a call to gtags, using universal-ctags. Command line global works as expected. 2) Using helm-gtags-dwim fails (with the following message, foo.bar: not found) 3) Using helm-gtags-find-tag works as expected

The following example can be used to reproduce the problem: a) Minimal example in R

cat << 'EOF' > foo.bar.R
foo.bar <- function(x) return(x)
EOF
cat << 'EOF' > foobar.R
foobar <- function(x) {
       y <- foo.bar(x)
       return(y)
}
EOF

b) minimal global configuration (with universal-ctags)

cat << 'EOF' > $HOME/.globalrc
default:\
    :tc=new-ctags:
native:\
    :tc=gtags:tc=htags:
new-ctags:\
    :tc=universal-ctags:tc=htags:
common:\
    :skip=HTML/,HTML.pub/,tags,TAGS,ID,y.tab.c,y.tab.h,gtags.files,cscope.files,cscope.out,cscope.po.out,cscope.in.out,SCCS/,RCS/,CVS/,CVSROOT/,{arch}/,autom4te.cache/,*.orig,*.rej,*.bak,*~,#*#,*.swp,*.tmp,*_flymake.*,*_flymake,*.o,*.a,*.so,*.lo,*.zip,*.gz,*.bz2,*.xz,*.lzh,*.Z,*.tgz,*.min.js,*min.css:
# Built-in parsers.
gtags:\
    :tc=common:\
    :tc=builtin-parser:
builtin-parser:\
    :langmap=c\:.c.h,yacc\:.y,asm\:.s.S,java\:.java,cpp\:.c++.cc.hh.cpp.cxx.hxx.hpp.C.H,php\:.php.php3.phtml:
# Plug-in parser to use Universal Ctags.
universal-ctags|setting to use Universal Ctags plug-in parser:\
    :tc=common:\
    :ctagscom=/usr/bin/ctags:\
    :ctagslib=$libdir/gtags/universal-ctags.so:\
    :langmap=R\:.r.R.s.q:\
    :gtags_parser=R\:$ctagslib:
# Configuration for htags(1)
htags:\
    ::
EOF

c) create tags, investigate global behavior (which is correct)

export GTAGSLABEL=universal-ctags
gtags
global foo.bar

it will answer foo.bar

d) Using helm-gtags with ess and (add-hook 'ess-mode-hook 'helm-gtags-mode) in foobar.R on the name foo.bar will work with helm-gtags-find-tagbut not with helm-gtags-dwim